Connected component labeling is an operation frequently used in image processing and computer vision applications to distinguish objects in a picture. Unlike human vision, a picture is “seen” by computer vision (or machine vision) in raster-scan order. In an example where a picture contains a “U”-shape object, since the picture is processed in raster-scan order, the machine will treat the left and right branches of the “U”-shaped object as two objects until the machine reaches the bottom of the “U”-shape object. The machine then realizes the two branches actually belong to one object.
In the conventional technique, the two objects corresponding to the two branches are merged by creating a component table entry with a link between the two branches. As there could be many objects in an image, a large table is needed to store information about each object, including an object ID and a link-pointer indicating whether an object is merged to another object.
It would be desirable to implement an ID recycle mechanism for connected component labeling.